Pull-on (also called pants type) disposable diapers having elastic members disposed between the waist opening and the leg openings to develop extensibility in the diaper width direction are known. For example, JP-A-9-84826 proposes a pull-on type disposable diaper, at least the front section of which has a first portion within an area 20 mm above the front end of the absorbent core and 20 mm below the front end of the absorbent core and a second portion defined between the first portion and the leg openings, wherein elastic members are spacedly disposed at a smaller interval in the first portion than in the second portion. The proposal aims at leak prevention without impairing the wearing comfort by making the contact with the wearer's body closer in the first portion than in the second one while substantially equalizing the planar pressure per given area between the first and the second portions.
A pull-on disposable diaper having elastic members disposed at an interval gradually decreasing toward the waist opening is also known from JP-A-U-6-421. This configuration allows for a strong contracting force being applied on the upper part of the wearer's hipbone.
However, the above-described configurations tend to make the diapers difficult to put on because of a strong constrictive force exerted in the waist portion. Moreover, the diapers tend to droop while worn, resulting in a sloppy appearance, hindrance to the wearer's movement, and fear of urine and fecal leakage.